The man who is serving a life sentence for a Fairview Township double murder has now been charged in a 30-year-old Lawrence County, Pa. murder cold case and may be connected to six to eight other homicides in northwestern Pennsylvania.

The new information was announced during a news conference Thursday morning. He is cooperating with investigators and answering their questions, police said.

Brown now faces charges for the 1988 murder of Bryce Tompkins, 45, of New Castle, according to Pennsylvania State Police. They include criminal homicide, two counts of aggravated assault, and intimidation of a witness. 

Hunters found Tompkins the day after Christmas lying partially submerged in Neshannock Creek near Dilworth Avenue, in Hickory Township, State Police said.

Tompkins had been shot twice in the back, according to investigators. Brown then dumped his body in the creek. The victim witnessed Brown commit burglary, and Brown was worried he would go to police, according to State Police.

State police identified Brown as a suspect early on, but they never had enough evidence to charge him.

According to the affidavit of probable cause, State Police had been monitoring Brown for the past 10 years. Investigators said he was involved with various motorcycle gangs in Erie. They were able to bring him in for questioning in Tompkin's murder in 2014, but Brown denied involvement.

It wasn't until after his arrest for double murder in Fairview, that State Police say he admitted his full involvement, during a police interview.

Brown was sentenced Sept. 19 to life without parole plus 40 years after pleading guilty to first-degree murder in the death of his wife Michelle Brown, 53, and third-degree murder in the death of his stepdaughter Tammy Greenawalt, 35.

Brown and Greenawalt were found dead inside the family's Fairview Township home on West Ridge Road back in March.

According to investigators, Brown bludgeoned his wife to death and rolled her body up in a carpet. They said he then stabbed his stepdaughter.

Brown also tied up his 14-year-old granddaughter in a bedroom for most of that weekend, State Police said. The teenager alerted authorities at school the following Monday.

State Police also told Erie News Now that Brown was a person of interest in a cold case in Corry, but investigators were not able to connect him to the crime. That case in Corry has since been closed.